单选题 The intellectually______ enterprise of science depends on free communication.
A. depressing B. depressed C. exhilarating D. exhilarated

【正确答案】 D

【答案解析】[解析] 四个选项的意思分别是：depressing令人沮丧的；depressed沮丧的；exhilarating 令人振奋的；exhilarated高兴的，振奋的。根据句子意思推出正确答案是D选项。例如，“The cold weather exhilarated the walkers．”(寒冷的天气使行人精神振奋。)